Crack resistance behavior of particulate reinforced composites at various test speeds and temperatures

摘要

Abstract In this study, the fracture behavior and characteristics of particulate‐reinforced composite materials were evaluated by performing wedge splitting tests. The crack resistance of the materials was evaluated using the crack tip opening displacement and crack tip opening angle. The composites were tested under various temperatures and test speeds. The digital image correlation method was used to analyze the strain field at the crack tip. The fracture surface under test conditions was observed using a scanning electron microscope. The test results showed that the fracture energy increased with decreasing temperature, and the crack resistance increased with increasing test speed. The crack tip opening angle is divided into an unstable region and stable region. The critical crack tip opening angle can be defined as the fracture mechanics parameter measured in a stable region. The surface strain fields obtained by digital image correlation method are distributed in the range from 1.5 % to 4.5 % at the initiation of the crack. A crack grows with dewetting phenomenon at the temperature range from 60 °C to −40 °C, and the crack propagates with fracture of ammonium perchlorate oxidizer particles at the glass transition temperature of −70 °C.